Clinical evaluation of optic atrophy in patients with neurological disorders

Optic atrophy is a pathological term applied to optic nerve shrinkage from any process that produces degeneration of axons in the anterior visual system (the retino-geniculate pathway). The pathologist can make the diagnosis of optic atrophy by direct observation of the histopathological changes in the optic nerve. The clinician is restricted to indirect evidence by observing the optic nerve as it enters the eye and through testing its function.

Fifty patients with bilateral or unilateral optic atrophy, were collected randomly from several teaching hospitals in Baghdad, Iraq, between August 1998 and June 1999. Those patients included in this study had ophthalmoscopic abnormalities of the optic disc in addition to defective visual function that could be localized to the optic nerve.

The defects in visual function varied between patients according to the disease process and duration of illness. Eight-seven percent of patients had visual acuity impairment, 74.4% had visual field defect, 58.5% had impairment in color perception, 64% had defective pupillary response to light and 88.4% had prolonged visual evoked potential (VEP) responses.

Patients who met the criteria for optic atrophy have different and unequal changes in optic nerve functions, ranging from 58.5% for color saturation test to 88.4% for VEP. Forty percent of patients with optic atrophy were discovered accidentally.